Fused silica: amorphous, extremely low coefficient of thermal expansion

Fused silica is the amorphous modification of high purity silica. It is synthesized using an electric arc at 2,000°C. The main feature of fused silica is an extremely low coefficient of thermal expansion (0.5*10-6/K).
Therefore these products are particularly suitable for special applications with alternating temperature loading. Grain sizes down to 1m are achieved by special iron free grinding and subsequent air separation. Thus we are able to offer grain size distributions down to submicrons. In addition to our standard products we offer a special grain size optimized grade as well.


  • hardness 6.5 (Mohs)

  • density 2.2 g/cm³

  • chemical inert

  • extremely low thermal expansion: 0,5*10-6/K (at 20-300°C)

Key applications:

  • electronics

  • casting resin systems

  • electrical insulation

  • precision casting

Fused silica products of the product range BRUCAFIL® are particularly suitable for the production of electronic parts and components, when low viscosities, optimized grain size distributions and adapted grain forms play an important role.


  • narrow grain size distributions

  • adapted grain shapes

  • low viscosities

Key applications:

  • EMC / CCL

  • Micro processors

With SILMIKRON 1171 we offer a synthetically produced amorphous silicon dioxide comparable to pyrogenic silica. This is a very fine product characterized by its high purity and its low specific BET-surface.


  • high purity

  • d50 = 0,3 µm

  • specific BET-surface of 30 m²/g

Key applications:

  • technical rubber parts

  • lacquers

High Performance Fillers based on amorphous silica: